/*******************************************************************************
 *     ___                  _   ____  ____
 *    / _ \ _   _  ___  ___| |_|  _ \| __ )
 *   | | | | | | |/ _ \/ __| __| | | |  _ \
 *   | |_| | |_| |  __/\__ \ |_| |_| | |_) |
 *    \__\_\\__,_|\___||___/\__|____/|____/
 *
 *  Copyright (c) 2014-2019 Appsicle
 *  Copyright (c) 2019-2024 QuestDB
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 ******************************************************************************/

package io.questdb.griffin.engine.functions.groupby;

import io.questdb.cairo.CairoConfiguration;
import io.questdb.cairo.sql.Function;
import io.questdb.griffin.FunctionFactory;
import io.questdb.griffin.SqlException;
import io.questdb.griffin.SqlExecutionContext;
import io.questdb.std.IntList;
import io.questdb.std.ObjList;

public class ApproxCountDistinctIntGroupByFunctionFactory implements FunctionFactory {

    @Override
    public String getSignature() {
        return "approx_count_distinct(Ii)";
    }

    @Override
    public boolean isGroupBy() {
        return true;
    }

    @Override
    public Function newInstance(int position,
                                ObjList<Function> args,
                                IntList argPositions,
                                CairoConfiguration configuration,
                                SqlExecutionContext sqlExecutionContext) throws SqlException {
        final Function exprFunc = args.getQuick(0);
        final Function precisionFunc = args.getQuick(1);

        if (!precisionFunc.isConstant()) {
            throw SqlException.$(argPositions.getQuick(1), "precision must be a constant");
        }

        final int precision = precisionFunc.getInt(null);
        if (precision < 4 || precision > 18) {
            throw SqlException.$(position, "precision must be between 4 and 18");
        }

        return new ApproxCountDistinctIntGroupByFunction(exprFunc, precision);
    }
}
